1. Field of the Invention
The present invention relates to a recording apparatus which judges whether a proper cartridge is attached thereto, process cartridge for use therein, cartridge judgement method, and image communication apparatus.
2. Description of the Related Art
Conventionally in recording apparatuses such as laser beam printers, since proper toners are limited depending on, for example, characteristics of photosensitive materials, it is judged whether or not an attached cartridge is proper. This judgement prevents image qualities from being provided with adverse effects caused by attaching an improper cartridge. As the above-described judgement, adopted is a method in which a main body of the recording apparatus reads an ID number incorporated into the cartridge to check up. As an example of the conventional recording apparatuses which judge the ID number, the laser beam printer is explained below.
FIG.1 is a schematic configuration diagram of a conventional laser beam printer. Conventional laser beam printer 500 is attachable and removal to/from a main body of the printer, and comprised of cartridge 502 into which fixed ID number 501 is incorporated, and main body 504 in which CPU 503 is mounted. When this cartridge 502 is attached to main body 504, CPU 503 of main body 504 reads ID number 501 incorporated into cartridge 502, and checks up the ID number. It is thus judged whether or not a proper cartridge is attached.
However in the conventional recording apparatus, since the ID number is fixed, the ID number is easy to copy, resulting in the problem that the cartridge can be imitated easily.
On the other hand, in order to prevent the ID number from being copied, there is a method for making the ID number variable, not fixed. However, to make the ID number variable, it is necessary to newly provide a special circuit such as a random number generation circuit. As a result, there are problems that the configuration of the recording apparatus becomes complicated, and that the cost thereof is increased.
An object of the present invention is to provide a recording apparatus capable of holding an ID number at the secret state, by making the ID number of a cartridge variable without adding large changes to a configuration of a conventional recording apparatus, a process cartridge for use in the recording apparatus, cartridge judgement method, and image communication apparatus.
The recording apparatus of the present invention acquires time data from a clock built in a main body of the apparatus, and generates first calculation data by calculating the time data with a predetermined calculation method. Meanwhile, in the cartridge attached to the main body, the time data is acquired from the main body, and second calculation data is generated by calculating the time data with the same calculation method as the above-mentioned predetermined calculation method. Then, as a result of comparing the first calculation data to the second calculation data, it is judged that the attached cartridge is proper when both of the data match, and it is judged that the attached cartridge is not proper when both of the data do not match.
Thus, the recording apparatus of the present invention employs the time data that is conventionally provided, and checks up the data acquired with the same algorithm by a CPU of the main body and another CPU at an IC card side. It is thereby possible to judge whether or not the cartridge attached to the main body is proper. As a result, it is possible to prevent the deterioration of image qualities caused by using an improper cartridge, and to always provide high image qualities to users. Further, since the recording apparatus of the present invention employs the time data acquired from the clock conventionally provided therein, it is possible to make the ID number variable without adding large changes to the configuration of the conventional recording apparatus.